Organic light-emitting elements, which have been researched and developed in recent years, are light-emitting elements that utilize light-emitting phenomenon of a solid fluorescent substance (For example, see Patent Literature 1). Organic light-emitting elements are manufactured by the following steps.
First, a reflective anode, which is a metal film, is formed on a substrate with an interlayer insulation film therebetween. Next, banks made of insulating material are formed to surround the edges of the reflective anode. Then, a hole injection layer and a light-emitting layer, which are organic films, are formed in the apertures defined by the banks. Here, as a constituent material of the hole injection layer, conductive polymer such as PEDOT/PSS (a mixture of polythiophene and polystyrene sulfonic acid) has conventionally been used.
Next, a cathode, which is a transparent conductive film, is formed on the light-emitting layer, and thus an organic light-emitting element is formed.